A gas turbine engine may be used to power various types of vehicles and systems. A particular type of gas turbine engine that may be used to power aircraft is a turbofan gas turbine engine. A turbofan gas turbine engine may include, for example, five major sections: a fan section, a compressor section, a combustor section, a turbine section, and an exhaust section. Another type of gas turbine engine that may be used to power aircraft systems is the auxiliary power unit (APU).
Gas turbine engines, such as the ones described above, typically operate more efficiently at increasingly higher temperatures. However, some turbine engine components, such as turbine blades and hubs, may experience greater degradation at higher temperatures. In addition, conventional blade configurations may not be ideal for the demanding performance requirements of next generation small gas generator turbine rotors.
In the past, turbine rotors have typically been fabricated as individual blade castings that are machined at the root and inserted into an inner hub which has been machined to accept the blade root machined contour. However, this configuration may result in non-ideal stress concentrations between the inner hub, the blade root, and/or the turbine blades.
More recently, a bonded dual alloy turbine wheel with single crystal blades has been proposed, which has performance advantages over mechanically attached blade designs. To facilitate producing a bonded single crystal blade dual alloy turbine wheel, the blades need to be a solid ring structure but with each blade single crystal aligned with the radial direction of the wheel. The interface between blade single crystals needs to mechanically behave with near parent metal properties.
Single crystal blade rings have been produced with transient liquid phase (TLP) bonding techniques to facilitate HIP bonding to a differing hub material. However standard TLP bonding techniques do not result in strong bonds at elevated temperatures as can be required from some applications. The lower strength is a result of a bond interface composition and microstructure that is quite different than the parent single crystal composition and microstructure. Thus, the prior art remains deficient.
Accordingly, it is desirable to provide a turbine engine rotor that is stronger and/or that exhibits increased reliability and/or durability. It is further desirable to provide a turbine engine rotor that results in improved performance. Furthermore, other desirable features and characteristics of the present disclosure will be apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.